When traveling around 35mph my tranny has started a slight vibration when (it appears) to be the torque converter locking in and out. It never does it at any other speed that i can tell but will go away when the OD is turned off. Any ideas? Fluid looks good and clean. it is the 46RE i believe

 

bump!

 

im gunna throw out the old remedy of it is probaly your TPS. when was the last time you changed it? the T/C locking and unlocking is the biggest sign of a TPS on the fritz.

 

I have never changed it. Would it throw a code or no? I have only had this truck about a year and a half so far. It has 109k in it. Have an idea where it is on these 4.7s?